1. Field of the Invention
This invention relates to a brush device wherein a brush integrally constructed of a commutator slide, a brush base and a terminal extending from the brush base is inserted into a terminal insert hole provided on a motor case cover which fixedly holds the brush, and a cut and raised piece provided on the base of the brush is caused to cut into the motor case cover so that the brush can be securely fixed to the motor case cover.
2. Description of the Prior Art
Heretofore, a brush device for a small electric motor has had a brush which is integrally constructed of, for example, a brush part and a terminal part and is fixed to a motor case cover with an appropriate means. In such a fixing means, however, there have been a number of problems such as unwanted movement or loosening of the brush with respect to the terminal insert hole provided on the motor case cover. To overcome them, various fixing means have been devised, and an exemplary structure takes the form of a cut and raised piece provided on the terminal part of the brush, the tip of which engages with a shouldered part provided on the inside wall of the terminal insert hole on the motor case cover to prevent the brush from coming out of the terminal insert hole. In this type of fixing means, however, a certain degree of dimensional tolerance is required to allow the cut and raised piece to engage with the shouldered part, with the consequence that unwanted movement of the brush cannot be perfectly eliminated. Furthermore, provision of such a shouldered part on the inside wall surface requires relatively complicated forming works.
As described above, various fixing means of the brush have heretofore been devised, but all of those means have problems such as structural complexity and inefficiency in assembly works.